Coming off of Fight Gone Bad and a bunch of snatches and overhead squats, I was feeling pretty cooked today, however I was excited by the CrossFit Endurance short intervals WOD of 10 x 30 seconds at max effort with 2 minutes rest, coming into each piece at full speed. This translates nicely into 20-stroke pieces at just under 40 strokes per minute, taking stroke #1 with 2-3 seconds left in the rest interval to get the wheel spinning as you start the 30-second work interval. I also believe that 30-second sprints are the perfect vehicle for determining what your sustainable max effort is on the C2. They are short enough to be done truly at max, but long enough to penalize you for bad technique. You can’t just muscle through, because with 10 intervals you will be so fatigued in the second half of the workout that your scores would drop rapidly.

How do I find my “MAX?”

As you know, I believe CrossFit Endurance is an extremely effective training technique for competitive rowing, but only if done at correct intensity. So how do you accurately find your limit? Answer: when you are able to deliver 6 or more intervals with a level of precision within 2-3%, you can confidently say that you have trained at your max for that day. I say “for that day” because you may be feeling good or lousy on any particular day, but you have to be able to consistently find the max you body is capable of on that day.

Why 6 intervals?

This is not scientific, but based on experience. The first interval on the C2 is usually significantly slower when doing a short interval workout because you are starting from a slow or stopped flywheel, which makes a huge difference on short pieces. Personally I find that it takes until interval #3 to really get my body to perform at max. I’m not sure why, but it may have to do with the aerobic nature of short intervals, which is a subject of debate. If that’s true then it would take several minutes for the aerobic “engine” to kick in. I also find that after 6 solid intervals I usually start to see my scores fade, and I have to work extra hard to maintain precision due to muscle fatigue. So that leads me to believe that my capacity for delivering consistent, quality intervals at truly max intensity is about 6.

Why is precision important?

If you have large variations between intervals, then it’s likely that none of your intervals was truly a maximal piece, and your body is still experimenting with technical, neurological, and psychological factors in an attempt to squeeze the most meters out of every stroke. Muscling out a single great interval but then not being able to replicate it will not allow you to gain the desired training effect. You need to practice enough to figure out where the redline is, and then consistently hit within 2-3% of that over and over again. I have found that the usual CFE prescribed precision is too loose for short intervals on the C2, and the 2-3% range is a better target to ensure a challenging target for consistent max performance.

What about a sprint?

You may find that in the later pieces you have to increase your stroke rate to maintain your results within the 2-3% range, but that just means you are keeping yourself at max output by any means necessary as your muscles fatigue. You will not be able to deliver significantly more meters per intervals even with what you perceive as an “all out sprint,” because your body is already at max output. If you are able to sprint for significantly more meters on the last piece, then you may not have been truly at max in the earlier intervals. I tried this approach in my last interval today, figuring I’d really “empty the tank.” It felt like I was going faster, but in the end I only delivered 2 more meters – hence the tank was already empty!

Here’s the results from today’s WOD, with a 2% over/under range on the chart. These were done at drag factor 110: